function deleteProduct(id){
	var product_name = document.getElementById("span-product-"+id);
	product_name.style.display = 'none';
	var product_id = document.form_regist.product_id.value;
	var product_ids = product_id.split(",");
	var product_ids_temp = [];
	var i = 0, j= 0;
	
	while (j < product_ids.length){
		if (product_ids[j] != id){
			product_ids_temp[i] = product_ids[j];
			i++;
		}
		j++;
	}
	document.form_regist.product_id.value = product_ids_temp.join();
}